Member postings for Geoff G

Thank you all, Gentlemen.

The email just didn't look right, but it's getting harder to sort the wheat from the chaff.

Life must be difficult for those trying to run a legitimate business, whether by phone, internet or post.

Thanks again.

Geoff G

I have received an email saying that I am entitled to £400 under the energy support scheme. There is a box marked "Proceed Now", which I am reluctant to click on, in order to register a claim. As a universal benefit, such a payment would surely be an automatic discount from one's bills.

Does anyone know if this is a scam, or am I just paranoid?

Geoff G

OK, Duncan. Well done, you win with that scenario! Just goes to show what thinking a problem right through to the end can do for you.

Geoff G

Hello, Geoff. I think that you will find that top and bottom dead centres (points of maximum swing of the beam) occur when a straight line is drawn through the centre points of the crank pin, the crankshaft and the con-rod / little end; i.e. when the centre line of the con-rod aligns with the crank pin centre line.

When the crank pin is 'up', it will be a little closer to the cylinder than the true vertical centre line and when 'down' will be slightly further away from the cylinder.

The angular displacement of the crankpin from the vertical cenre-line of the crankshaft will not be the same for TDC and BDC, but the difference is very small and of no account for all practical purposes.

Geoff G

Thank you for the link, John. All very technical, this internet stuff - it's not only my son who is cleverer than me!

Geoff

Gents, a search for "dave goodchild antikythera" will bring up info on the machine (working) that my son made . . . . out of wood, proving that metal is not the only material for precision mechanisms. See particularly the Youtube offerings. All of the components were cut on a jig saw, inluding the countless gear teeth and even the bevel gears.

A lot more clever than his proud dad!

Geoff

Like most of us, I have tried a number of materials, but most are unsuccessful, due to colour, scale appearance or the inability to transmit power. Eventually, I tried ribbon made of man-made fibre (girls' hair ribbon type of thing) - available in wide range of colours and widths from haberdashers and fabrics shops. Cut a piece a little bit overlength, heat-seal the ends with a flame, and then sew the ends together with little figure of eight stitches, over and under the stiff ridges created by the flame. I takes a little while, and a number of failures, to get the length just right. Because ribbon is smooth and slippery, I then smear the inside face with solvent free contact adhesive which seems to retain a grippy, rubbery surface to ensure a positive drive.

Good luck,

Geoff

Why learn a foreign language when there are enough anomalies in English to confuse us for a whole lifetime.

Teacher: "Sugar is the only word in the English language wher the 'S' gives a 'sh' sound without the need for an 'H'.

Student from back of class: "Are you sure?"

Geoff

Just a suggestion - maybe the taper is the clue. A bronze olive would sit in there and a flare in the end of the steam pipe would fit the other end of the olive. a matching taper in a loose flange would permit the whole lot to be clamped together. I think this sort of connection was favoured in flash steam engine construction. Hopefully there is a basic sketch below.

The letter H is called aitch, not haitch, as so many seem to believe. it really annoys me!

Geoff

Drawings and details of the version built by Brian Perkins were serialised in Model Engineer, starting 4th February 2005 and ending 27th May (alternate issues, as per usual).

Geoff

I think that Nick Clarke, at the top of this topic, has it right. With its very limited range and the connections to either side of the manometer, it is clearly intended to measure the pressure difference between two streams of gas (carb intakes, or whatever. The actual pressure in the system is not relevant, only the variation between the two. The use of water in the u-tube will, of course, give a much more accurate reading (12 times better?) than mercury would, never mind the problems which Neil envisages with the mercury / brass combination.

Geoff G

Back in the mists of time, I attended model engineering classes at the local college and on the tool racks there were dreadnought files. Nine teeth per inch, single cut, curved across the width of the file; good at removing large amounts of metal and not easy to clog. They are still available in a range of sizes, either flat or half round. Search "dreadnought files" - plenty of suppliers.

Geoff

Yes, always excellent and helpful service. As well as the usual pieces of steel, aluminium and brass, they supplied me with a 120mm long piece of 295mm O/D, thick walled steel tube. Where else would I find that!

Geoff

My copy of 4584 has not arrived yet - postal area EX, in Devon. I saw that it was in the shops at the end of last week.

The distribution system does seem to have problems; I think that this is the sixth issue that has been late, or missing altogether, in the past twelve or fourteen months. Very irrritating for a long term subscriber.

Geoff

I'm with Simon Collier - fabricate the bend. I have done it by cutting the parts at 22.5 deg, holding them in a jig (rough!) and silver soldering. The application of a little time and an assortment of files should produce a visually passable result. This method should suit any size, in any material. In view of the use of butt joints, I guess that working pressure sould be limited. A couple of pics to show the idea:

Much as we want you back in your editorial chair as soon as possible, Diane, be sure to listen to the Doctor and take as much time as neccessary, to ensure your full recovery.

Best wishes,

Geoff G

Plus 1 for non delivery of issue 4559. I live near Exeter, in Devon; Could this be a repeat of last year's loss of a whole batch of mags destined for the south of the country? It has certainly happened to me several times in the past and is rather annoying because by the time you realise that you are not going to get your copy, the shops have sold out. I also emailed [email protected] about 35 hours ago and, so far, have only received their automated acknowledgement.

Geoff G

Very useful bit of kit. The great benefit of a hold-fast is that, by working away from the clamp, it permits planing or scraping of very thin pieces of wood which would buckle and break if you tried to work them up against a bench stop.

Geoff

I have had to resort to purchasing a copy of ME 4546 from Smiths. There is still no response to my email sent to the subscriptions office on 1st Nov, so have sent another one.

Geoff